Inverted Quantum-Dot Light-Emitting Diodes with WO3/Zinc-Tin-Oxide Electron Transporting Layers

Abstract

We demonstrate the enhanced efficiency of inorganic/organic hybrid quantum-dot light-emitting diodes (QD-LEDs) by adopting WO3/zinc-tin-oxide (ZTO) as an electron-transporting layer (ETL). The relationship between the ETL properties and device performance was explained by the effect of the WO3 layer on electron transport, which was investigated using thin film analysis methods. A maximum luminance of 700 cd/m2 and current efficiency of 0.43 cd/A were obtained from a QD-LED with 40-nm-thick WO3. The current efficiency was more than twice that of a device without a WO3 layer.